1. Field of the Invention
The present invention relates generally to frames for transparent or translucent displays, and more particularly, to side-lit displays.
2. Description of the Prior Art
Displays of art and information have always been a part of man's life. Most such displays have been front lit, where light shines on the object of interest, and front lighting continues to dominate, from the heights of art to the mundane such as posted schedules at bus stops.
With the advent of artificial lighting and the ability to produce and reproduce pictures and information on transparent or translucent materials, backlit displays have evolved, where light shines through the object being displayed.
One form of backlit display uses a light box containing a light source such as a plurality of fluorescent lamps, with a transparent or translucent display object on the front of the light box. Unless the light box has sufficient depth to provide for diffusion of the light from the lamps, a diffusion layer is placed between the lamps and the display object to diffuse the light, providing even levels of light over the display object. Such light boxes tend to be large and bulky to house the fluorescent lamps. The lamps and their ballasts generate heat. Fluorescent tubes have a finite operating life and must be replaced when they fail. With these limitations, light boxes are widely used to display pictures and information.
A premier example of a light box display was the Kodak Colorama at the East balcony of New York City's Grand Central Terminal, which displayed 18×60 foot rear-lighted transparencies for forty years, from 1950-1990.
More mundane examples of fight box displays include back-lit advertising displays in airports and other public and commercial venues, menu and product displays at fast food establishments, and the like.
Back-lit and light box display technology changed with the development of inexpensive light emitting diodes (LEDs), particularly with the availability of powerful LEDs capable of producing white light.
With LEDs, the bulky light box filled with fluorescent tubes is transformed into a thinner package featuring a side lit light guide.
The light guide is typically an acrylic plastic panel 4 mm or more in thickness with a white reflective backing and a treatment for dispersing light from the front surface of the panel. This treatment may be in the form of etched or printed patterns on the front surface of the panel, or in small particles dispersed within the panel.
The light guide panel is side lit using LEDs. LEDs are mounted to direct their light into the edges of the light guide panel. Depending on the size of the light guide panel, the intensity of the LEDs, and the amount of light required, LEDs may be placed along one or more sides of the light guide panel.
The resulting side lit framed panel is much thinner than older light boxes, and relatively maintenance free through the use of long life LEDs.
A problem arises with these panels. For commercial applications involving large quantities, they are economical when compared with older technologies.
But for other than standard sizes and large quantities, the economies are not present. Frames for side lighting are made in standard sizes in large quantities. But such frames are not amenable to the myriad of shapes and sizes required for framing art in the real world; art seldom deals in standard sizes, nor can such art be easily resized to fit a standard. Nor is it economical to build one or two custom-sized side lit frames at a time.
What is needed is a way to adapt such side lit frames to a wider range of sizes.